There is a way to assign HA and sidechain en V3?
You can do the assignment in several ways. (I`m assuming you know which peak (dimension) you are trying to assign.)
Peak Assigner (AP or Assign / Peak Assigner)
With the peak assigner, simply type HA into the Atom Name box or choose HA from the drop-down menu and then click on Assign (obviously also select the correct NmrChain/Residue/Type if required/known).
NmrAtom Assigner (AN or Assign / NmrAtom Assigner)
Click on the gear icon to open the settings panel and then swith Mode from Backbone to All. For a proton dimension this should then show all possible NEF atoms names.
Drag & Drop from sidebar
Alternatively, if you already have an HA NmrAtom, you can always drag an NmrAtom from the sidebar onto a selected peak in order to make an assignment.
Hope that helps.